1. Field of the Invention
The present invention relates to improvement of a plate-type ozone generator for generating high-concentration high-purity ozone and, particularly, to a plate-type ozone generator which is capable of generating high-purity ozone that is not contaminated with metal while the apparatus eliminates the deterioration of a gasket used in a discharge cell for forming a discharging gap, and prevents the leakage of ozone, a harmful gas.
2. Description of the Related Art
Ozone, having a strong oxidizing ability, has long been used as an oxidant in chemical industries, and has been widely used to sterilize, deodorize and decolorize waters. In recent years, ozone has been widely used as a fine chemical material.
Various methods have been known for generating ozone. These include a method of radiating ultraviolet light to oxygen, and a method of electrolyzing water. In order to continuously generate a large quantity of ozone for industrial use, a method utilizing silent discharge is generally used. In this method, a discharging gap is formed between a pair of opposed electrodes, and a dielectric is provided on either the electrode surface of one of the electrodes or the electrode surfaces of both electrodes. An AC voltage is applied between the electrodes to cause continuous silent discharge between the electrodes through the dielectric while air or oxygen gas flows through the gap between the electrodes so that ozone is generated. One type of an ozone generator for industrial use is a plate-type ozone generator.
As shown in FIGS. 5 and 6, a conventional plate-type ozone generator includes a pair of discharge cells, each cell comprising either a high-voltage electrode 11 or an earthed electrode 12 and a dielectric layer 13 disposed on the electrode surface of the electrode 11 or 12. The discharge cells are opposed with a separator 14 therebetween, and formed into an integral structure by applying a silicone adhesive on the periphery of the cells, thereby forming a discharging gap 15. A radiator 16 is provided on the outer surface of each discharge cell. Further, holes 17 and 18, arranged in a diagonal direction, as shown in FIG. 6, open into the discharging gap 15 so that when air or oxygen is introduced through one of the holes 17 while silent discharge is caused, ozone can be generated and collected through the other hole 18. Normally, a silicone gasket 19 is disposed on the periphery of the mutually opposed surfaces of the discharge cells in order to form the discharging gap 15. However, the gasket, which is continuously exposed to high-concentration oxygen during operation, easily becomes impaired, and has its sealing performance deteriorated. Thus, the conventional ozone generator fails to provide satisfactory reliability and stability.